a. Fats
Edible fats and oils ("fats") are organic compounds composed of three fatty acids attached to the glycerol molecule and are also known as triglycerides. Major types of fatty acids are saturated, polyunsaturated and monounsaturated.
The body needs a small amount of fats to carry fat soluble vitamins, to store energy, to cushion and protect vital organs, to insulate the body thermally, to give shape to the body and to regulate cellular metabolism. Non-essential fatty acids are made by the body itself, but essential fatty acids must be obtained dietetically through the foods we eat. But, fatty foods are high in calories (9 calories per gram of fat) and too much dietetic fat is bad for many reasons.
It is now well recognized and generally accepted, as demonstrated and proven by numerous scientific studies, that there is a close relationship between the amount of fat in one's diet and the risk of developing a life threatening disease. Fats saturated with hydrogen cause the body to produce more cholesterol which has been linked to coronary disease known as atherosclerosis (plague build-up on artery walls). Oil, composed mainly of polyunsaturated fats, in large quantities may increase the risk of cancer, and high fat diets generally have been scientifically linked to breast, colon, pancreas and prostate cancer. Importantly, fatty foods cause obesity. One reason is that it takes less energy (fewer calories) to convert fat to stored fat cells in the body than, other foods, such as, foods high in carbohydrates.
Fats and oils are now recommended by the U.S. government to be the smallest part of one's diet and are to be used sparingly. Most major health organizations now recommend that not more than thirty percent (30%) of the total calorie intake be from fat, and it has been scientifically established that keeping the dietetic percent calories from fat below ten percent (10%) on average, not only helps to avoid obesity, coronary disease and certain cancers, but also, can actually reverse atherosclerosis over a long time period. The Food and Drug Administration ("FDA") has now approved a new food label which will require listing the grams of fat and the calories from fat in the food.
One tablespoon of a vegetable oil contains 14 grams of fat, 126 calories and 100% of the calories are from the fat. Most common oils and fats are high in saturated fats and/or polyunsaturated fats.
Thus, it is now well recognized that one of the best choices of foods is a fat-free food. As defined by the FDA, fat-free means the food product must have less than 0.5 grams of fat per serving. It is an object of the present invention to produce fat-free food products.
b. Potato Chips
Potato chips are a favorite snack food for all age groups.
Conventional potato chips are deep-fried in fat and are very high in calories. The typical finished potato chip contains 30-45% fat by weight and less than 5% moisture by weight (unless otherwise indicated by the context, all percentages of contents listed herein are by weight). A single one ounce (1 oz.) serving of any conventional potato chip contains about 10 grams of fat, 150 calories and 60% of the calories are from the fat. Not only is the deep-fried process difficult to control and inefficient, often resulting in overcooked chips, but also, the moisture and fat left in the product react together to shortly impart a rancid odor and flavor and loss of crispness which limits effective shelf life to about two weeks.
Because of the long term heavy emphasis on health and fitness and the strong trend toward greatly reducing the amount of fat in the food we eat, there has been a long felt need for a fat-free potato chip snack food product. It is an object of the present invention to produce fat-free snack food products, including potato chips.
c. Prior Low Fat Or Fat-free Potato Chip Processes And Products
Having recognized the long felt need, other inventors have attempted, without success, to produce a commercially acceptable fat-free potato chip that looks, feels and tastes like a conventional fatty potato chip cooked in fat.
(1). Prior Processes Extracting Lipids From Deep-fat Fried Potato Chips
The earliest and most obvious way to reduce the fat content of the finished potato chip product was to remove some of the oil absorbed by the food pieces during the deep-fat fried step. Various techniques included removing the pieces from the deep-fat frier while their moisture content was still relatively high (5-20%) and finishing heating by a variety of techniques, such as, hot air drying (including non-recirculated air), radiant heating, microwave heating or combinations thereof. These processes failed to produce a fat-free product.
(2). Prior Low Fat Processes
The next early attempts to reduce the fat content of the finished potato chip were by completely eliminating, nullifying or limiting the duration of any necessary deep-fat frying of the potato pieces. In a process to Yuan (U.S. Pat. No. 4,283,425) a single step of heating by microwave (910-915 mhz or 2400-2500 mhz) was used as the sole means to remove moisture and was alleged to produce a crispy, fat-free chip having the uniform color and taste of a deep fried potato chip. But, this product was not commercially successful, probably because the actual appearance and taste did not live up to its billing. Also, the non-standard equipment needed to make the product required significant investments. Moreover, optionally, the slices were dipped in or sprayed with an edible oil prior to final microwave cooking obviously to restore that characteristic desirable deep-fat fried taste. The added fat content of 3-5% by weight of this product equated to 0.85-1.43 grams per one ounce (28.5 gms.) serving, too high to be classified fat-free. Thus, this product was basically a "low-fat" potato chip.
In another process to Haydock (U.S. Pat. No. 4,749,579) standard potato chip making equipment was used, but the potato slices were first salted in depth, air dried and then preheated with infrared radiations before deep-fat frying. The finished "lite" potato chip product still had 26-32% fat by weight, whereas "regular" potato chips had 36-42% fat by weight. In another variation to Neel (U.S. Pat. No. 4,933,199), par-fried slices were de-oiled to less than 25% fat by passing superheated steam through them in a controlled oxygen environment followed by dehydrating to produce a finished potato chip having less than 2% moisture. In a still further variation of this process to Prosise (U.S. Patent) the slices were first coated with polyvinylpyrrolidone to provide increased resistance to oil absorption during the deep-fat frying step to produce a finished chip having 23% fat.
In still another process to Dreher (U.S. Pat. No. 4,756,916), monolayered potato slices were sprayed with a partially hydrogenated cottonseed and soybean oil mixture, steam blanched, parabaked in a three zone oven at 425.degree. F. (218.degree. C.) to 15% moisture and final baked at 310.degree. F. (155.degree. C.) to 2% moisture producing a final potato chip having 10-18% fat by weight.
These products were not practical, fat-free and tasty.
(3). Prior Genuine Fat-Free processes
((a)). Infrared-Microwave-Infrared
Finally, it also has been known to produce potato chips genuinely without the use of any form of cooking oil whatsoever. In a continuous process to August (U.S. Pat. No. 4,800,090) sliced potatoes were first subjected to an infrared (high intensity 46 micron wavelength) heating step to warm their exterior, then to a microwave energy (915-2450 mhz) heating step to warm their interior, and finally to another infrared (4-6 micron wavelength) heating step to brown them into a crisp, fat-free, potato chip snack food product that was low in calories and had a long shelf life.
((b)). Microwave-Cold Water Rinse-Radiant Heat Batch
A further variation of a "no cooking oil" process was the batch process of Kloos (U.S. Pat. No. 4,906,483) in which the microwave cooking step was employed early in the process to activate the release of starch while the potato slices were still immersed in water followed by a cold water rinse and final cooking in radiant heat until brown and crisp to produce a fat-free potato chip.
((c)). Cooking Between Dual Relieved Opposed Surfaces
A still further fat-free process was to Childers (U.S. Pat. No. 4,919,965) which simultaneously final cooked the potato slices by compressing them between dual opposed heating surfaces which were 50% relieved driving the moisture into the voids in the cooking surfaces to produce a fat-free potato chip.
None of the genuine fat-free processes have been commercially successful. Either the texture or taste of the product has been unacceptable to consumers or the process was not continuous and therefor impractical in large quantities.
Thus, the market still cries out for an economically made, tasty, genuine, fat-free potato chip product.
It is an object of this invention to fill this long felt need by making a fully cooked fat-free potato chip product with a long shelf life that looks, feels and tastes like a conventional potato chip in an economical continuous process without using any cooking oil whatsoever.